Focusing mechanism for cameras



r h 1927. Ma c R. KROEDEL. ET AL FOCUSING MECHANISM FOR CAMERAS Ori inal Filed Sep 8. 1922 2 Sheets-5heat 1 March L 22 1927.

R. KROEDEL T AL FOCUSING MECHANISM FOR CAMERAS Original Filed Sept. 8. 1922 2 sh t -sh t 2 Patented Mar, 22, 1927.

UNITE TATES PATENT OFFICE.

ROBERT KEOEDEL AND GEAR/LES F. SPEIDEL, OF ROCHESTER, NEW YORK, ASSIGNORS TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEl/V YORK.

FOCUSING MECHANISM FOR CAMERAS.

Original application filed September 8, 1922, Serial No. 586,990. Divided and this application filed May Our present invention relates to photography and more particularly to the focusing mechanism for cameras and it has for its object to provide a simple, efficient and convenient means, capable of fine adjustment, for operating an extension bed of a camera relatively to the main bed. To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claim at the end of the specification.

In the drawings:

Figure 1 is a side view of a folding camera provided with a focusing mechanism con structed in accordance with and illustrating one embodiment of our invention;

Figure 2 is an enlarged fragmentary top plan view of the bed thereof;

Figure 3 is a fragmentary section on the line 33 of Figure 2;

Figure 4 is a similar section showing the position of the adjusting means when the extension bed is extended;

Figure 5 is a transverse section through the bed on the line 55 of Figure 2 and Figure 6 is a fragmentary section on the line 66 of Figure 2.

Similar reference numerals throughout the several views indicate the same parts.

Our improved focusing mechanism is particularly applicable to folding pocket cameras of a familiar type and we have illustrated it in connection with such a camera this application being a division of our pending application Serial No. 586,990, filed September 8th, 1922. Referring more particularly to the drawings and to Figure 1 thereof the camera comprises generally a body 1 and a hinged main bed 2 at the front thereof which when closed constitutes a door, and which when extended as in the figure performs the function of a bed and support being fitted with a folding leg 3 at its forward end. Locking braces l hold the bed rigidly extended and a lens carriage 5 connected to the body by a bellows 6 travels on the bed in connection with an extension bed hereinafter described between an extended focusing position such as that shown and a- Serial No. 715,529.

folding position within the body 1 wherein the bellows and front are normally stored. It is the mechanism whereby this extension bed is positioned with which the present invention is concerned.

Referring more particularly to Figures 2 and 5, the main bed 2 (leather covered at 7) is provided at its sides with lateral or inturned tracks 8 to slidably receive an extension bed 9 having runners 10 at its edges fitting the tracks. The extension bed, normally and when retracted, is substantially coincident with the main bed and the extension bed is in turn also provided with tracks 11 on and between which slides a carriage 5 carrying the front frame 12 and lens board 13. The carriage and front is drawn in and out by grasping the finger pieces 14 and 15, the former of which is fixed and the latter movable to release a suitable clamp for lockin the carriage in any position in which it is left on the extension bed 9, but these details are of no consequence here. A suitable stop on the extension bed indicated at 16 in Figure 5 limits the forward movement of the camera while in moving rearwardly to folding position it rides off of the rear end of the extension bed 9 and onto aligned tracks within the body 1 (not shown) as usual. I

In the practice of our invention we move the extension bed 9 relatively to the main bed 2 by means of a double screw having a right hand threaded portion 17 at one end, a left hand threaded portion 18 at the other end and an intermediate thumb piece or knurled operating knob 19. The screw portion 17 is threaded into an upwardly and inwardly projecting lug 20 on the side of the main bed 2 while the screw portion 18 is similarly threaded into an upstanding lug 21 on the extension bed 9 and which is aligned with the first mentioned lug. This arranges the thumb piece 19 conveniently to be rotated by overshot pressure of the thumb of the user as he holds the camera by grasping the bed, and it is obvious that the right and left hand screw arrangement causes the beds to move relatively just twice as fastas would be the case if a single screw were used which cri gives a rapid adjustment and yet a sensitive one when desired. The two extreme positions of the screw and of the extension bed are shown in Figures 3 and 4, the bed being extended in the latter view.

To prevent the screw from jamming on the one hand and from becoming detached from its lugs on the other, we prefer to otherwise limit the resulting movement of the extension bed'9. Referring to Figure 2 there is attach d to one side of the extension bed a scale plate 22 hearing two scales 23 and graduated in terms of different units of liliear measurement as, for instance, feet and meters for selective use. Spaced lugs 25 and 26 on the adjoining edge of the bed plate 2 are provided with marks 27 constituting indicators one for each scale. A laterally projecting lug 28 near the center of the scale plate 22 travels between these lugs 25 and 26 with the relative movements of the beds and engages them alternatively as stops.

l-Ve claim as our invention:

In a photographic camera, the combination with a main bed having an upwardly and inwardly projecting threaded lug on one side thereof and an extension bed guided on the main bed and having an upwardly and laterally projecting threaded lug thereon alined with the first mentioned. lug, of a screw hav- ROBERT KROEDEL. CHAS. F. SPEIDEL. 

